Materials useful for packaging electronic components preferably exhibit certain properties. For example, the packaging material should provide dissipation of static electricity and shielding from static discharges and electric fields that may be generated, e.g., when the electronic component moves inside the package or when the packaging material is rubbed against other materials. The packaging material should also function as a barrier against moisture vapor and oxygen to protect the electronic component from degradation while it is being stored. While it is not a requirement of the packaging material, it is usually desirable for it not to be opaque, as a consumer of the electronic component would want to ensure that the proper component is used for the intended application.
While there are variations on the construction of packaging materials for electronic components, many share certain common features. For example, it is typical for the packaging material to contain a carrier or a substrate that provides the overall integrity and strength of the packaging material. In many constructions, the substrate is metalized. That is, on at least one of its surfaces, the substrate can be coated with a conductive metal layer. Typically, the metal has been sputter coated or vacuum deposited onto the substrate. Typical metals include, but are not limited to, aluminum, cadmium, chromium, copper, lead, nickel, zinc, and combinations thereof. Perhaps the most commonly used metal is aluminum. When these metal layers are used as the conductive layer, the packaging material, in its overall construction, can transmit some visible light, i.e., it can exhibit some transparency. It is well known, however, that as one increases the thickness of the metalized layer, the transparency of the construction is reduced. One reason why it may be desirable to increase the thickness is to increase the construction's performance against moisture vapor and oxygen ingress. Another reason may be to increase the conductive performance of the construction. Some constructions also include antistatic coatings, typically as the coating exposed to the atmosphere and/or to the electronic component.
While the technology of the prior art may be useful, other constructions for materials useful for packaging electronic components are desired.